Hierarchical Functionality Prioritization in Multicast ISAC: Optimal Admission Control and Discrete-Phase Beamforming

TL;DR

This paper addresses hierarchical resource allocation in ISAC systems, proposing an exact MILP approach for joint admission control and discrete-phase multicast beamforming, achieving over 39% performance improvement.

Contribution

It introduces a globally optimal MILP reformulation for hierarchical resource allocation in ISAC, outperforming baseline methods.

Findings

Proposed an exact MILP reformulation for the problem.

Achieved over 39% performance improvement compared to baselines.

Demonstrated effectiveness in joint admission control and beamforming.

Abstract

We investigate the joint admission control and discrete-phase multicast beamforming design for integrated sensing and communications (ISAC) systems, where sensing and communications functionalities have different hierarchies. Specifically, the ISAC system first allocates resources to the higher-hierarchy functionality and opportunistically uses the remaining resources to support the lower-hierarchy one. This resource allocation problem is a nonconvex mixed-integer nonlinear program (MINLP). We propose an exact mixed-integer linear program (MILP) reformulation, leading to a globally optimal solution. In addition, we implemented three baselines for comparison, which our proposed method outperforms by more than 39%.